Labyrinth gland for machine shafts



All@ 39, 1932- w. VAN RIJSWIJK 1,873,988

LABYRINTH GLAND FR MACHINE SHAFTS Filed April 6, 1927 '45 tionof a third. form.

Patented Aug. 30, 1932 `Niilao STATES.

Larissa PATENT "rra WILLEM VAN RIJsWIJiI, or ENNETBADEN, swrrznn'iainn LABYRINTH `GLAITD FGRMACINE SHAFTS Application filed April 6, 1927, Serial No.

preventing leakage and escape of gases f through the s-anie.

` practice.

' 1 Other and incidental .objects willbe pointedout or indicated hereinafter or will appear to one skilled inthe art upon an understanding of-the invention or its employment 1n In the lification, I illustrate `three arrangements of structure representative of: some embodiments of the invention,'the same being shown in diagrammatic fashion. It is to be understood, however, that th-ese are presented for illustrative purpose and are not to be .construedin any fashionl to have the effect of limiting the claims .to these particular ar-A -rangements orV short yof the true and most comprehensive scope of the invention in the art. f

In said drawing,

Fig. 1 is a diagrammaticvillustr'ation in the nature of a longitudinal. section through' 'a gland, showing a part of the operating shaft with which it cooperates and a portion of the machine cas-ing served by the Vgland and the shaft;

Fig. 2 is a similar section, diagrammatically illustrated, of a modified arrangement of apparatus; and 1 y Fig. 3 is asimilar diagrammatic illustral The present invention relates to a type of gland which is adapted to accomplish its seal- 'infr action without the use of a liquid sealing mediunn Certain advantages are to be attained by an eective gland of this type, as

drawing forming a part of this spec- 181,595, mi in. Germany api-111,5, 1926.

:it precludes the Possibility/,lof the absorption of an externalsealing medium by the working v iuid within the machine. By virtue of the present invention, thereis accomplished .a

gradual reductionof the pressure of working fluid which may bepworking outY along the shaftpso that its escaping tendencyis overcome, the greaterproportion of the working i, fluid being returned to the'machine or system and' all of the remainder being properly controlled and directed to a proper point of dis- -posal for recovery orfor discharge at afpoint where it will occa'sionno inconvenience or harm. A more 'detailed understandingof the invention may be obtained by consideration of the illustrative arrangements shown in the drawing. In the arrangement; illustriated in Fig. 1,'tlie reference numerallOy designates a vportion of the machine casing.- such as of a steam turbine or a compressor,

wherein a fluid isconfined under presure, and 11 designates a portion ofthe-operatingshaft which serves the'machine, the same being led lout from the casing'through a suitable gland `12, fofthe labyrinth type, for example.. This gland is provided with lantern spaces or tapping chambers spaced at appropriate intervals along the shaft. Of these tapping chambers or channels, :the one nearest the machine casing, designated 14 in the drawing,fis con. nected by meansfof suitable conduits 15 and 16, ,with a portion VofltheV machine chamber which carries `a low internal pressure. vFor purpose of convenience I will designate this the reducing tapping. p Next in order to the reducing trapping.v -is an intermediate tapping 17, which I will designate the krecovery tapping, and neXt in order from this is atapping 18 which I will designate the exhaust tapping. rlhe recoverytapping is connected with the pipe 16by way of'a pipe 19 and an ejecting device 20 which is supplied with operating fluid fromy a high pressure point in the machine Vby way of the pipe 21. Pipe 21 is controlled by a valve which is regulated by an automatic pressure regulator 22 in accordance with pressure in'tapping space 17. The pressure in the 'reducing tapping 14 is controlled by the 'pressure in the machine at the point where pipel is connected thereto, and is above atmospheric pressure due to the fluid finding access thereto from the high pressure end of machine casing 10 through the operating clearance between the shaft and the gland. By the pressure regulator 22 the pressure in the recovery tapping 17 is maintained at a point only slightly above atmospheric, but below the pressure in reducing tapping 14. When the pressure in the recovery tapping 17 tends to exceed the maximum, the pressure regulator 22 opens its valve and admits'pressure fluid to the ejector 2O to draw fluid from the tapping 17 and raises it to the pressure in pipe 16 so that it may be returned to the operating chamber of the machine. Consequently, if the pressure at the point where pipe 16 is connected to the machine chamber is considerably higher than atmospheric pressure so that there is a tendency for leakage from the reducing tapping 14, the greater .porti-'on of the Huid reaching the recovery tapping 17 is returned. It follows, therefore, that the pressure of the escaping fluid is reduced at the reducing tapping 14 to that existing` in the low pressure portion o'f the machine chamber, and the pressure of fluid leaking from the chamber 14 through the operating clearance is further reduced in the recovery tapping 17 to a point only slightly in excess of atmospheric pressure. The furtherI leakage from the recovery tapping 17, consequently,

Vwill be very slight, so that there will be very rlittle loss from themachine. In order that `this small residual leakage may be recovered or may be conveyed to a point of disposal where it will occasion no harm or inconvenience, the exhaust 'tapping 18 is provided with I a pipe 24 through which the fluid is conveyed to a suitable point of disposal, the fluid being drawn o ff through said pipe by suction which maintains the exhausttapping 18 at sub-atmospheric pressure. The pressureV in lexhaust tapping 18 is controlledby a pressure `regulator .25 which opens a valve in pipe24 to'render the suction effective whenever the ypressure vin pipef 24 and tapping 18 reaches arpredetermined maximum. 1

In the arrangement illustrated in Fig. 2,

i the parts correspond to those shown in Fig. 1,

' employed in place of the ejector 20, saidcomwith the exception that a compressor 26 `is 4pressor being operated by gearing' connec- 'tions 27 with the shaft 11. Y

In the arrangement illustrated in Fig; 8,

" the organization is as described with reference to Fig. 1, with the addition of an impeller 28, carried by shaft 11 for discharging fluid from the exhaust tapping 18 to the exhaust pipe 24 whereby it is led to a suitable absorption or recovery device 29. It will be. understood that the absorption or exhaust tapping 18 from the recovery tapping 17, as well as air drawn in from outside the gland, are compressed at the periphery of the impeller to a degree suicient to overcome the frictional resistance in the exhaust pipe. In this case, the pressure in the recovery tapping 17 must be maintained slightly above the final pressure -of the impeller 28, .and this may be accomplished automatically through the medium of the vpressure regulator 22 'which operates ata selected differential between the pressure in recovery tapping 17 and the final impeller pressure in exhaust tapping 18.A

It is believed that the operation of the several devices is clearfrom the foregoing description without 4further detailed repetition, and that from the. same it.l is apparent that leakage through the gland is delinitely'convtr0lled-.vand thatv alli fluid tending to'escape `through the gland is either returned to .the

machine or disposed of in a selected and definitely controlled fashion. v

WhatI-claim is: v

1. In a sea-ling gland for machine casings Vhaving a member extending therefrom, a

gland structure associated with the casing about the member and having a plurality of chambers'formed therein, a conduit connecting two of the chambers to a space at superatmospheric pressure, a conduit connecting another of the chambers to a space at subatmospheric pressure, and a pressure-operated valve for `automatically maintaining substantially atmospheric pressure 1n one ofthe two chambers connected to the space at super-atmospheric pressure.

2. In aV sealing gland for machine casings having a member extending therefrom, a

glandV structure associated with the casing@ about the member and having a plurality of chambers formed therein, one-of said charn- `bers being arranged to receive a uid from a space of high pressure in said casing, a conduit connecting the said one of said chambers with a second of said chambers and with a space at super-atmospheric pressure lower than the pressure in the said space of high pressure, a conduit connecting a 4third chamber to a space at sub-atmospheric pressure, means in the conduit connecting the first and second chambers operative to cause flow of fluid from thev said second chamber to the said Vspace atsuper-atmospheric pressure by way of the first said conduit, the said means being connected withithe said space of high pressure, and a valve controlled by pressure in the second chamber operative to control operation of the said means to cause the pressure in the said second chamber to Vbe maintained at substantially atmospheric pressure.

8. In-a sealing gland for machine casings having amember extending therethrough, a gland structure associated with the-,casing about the member and having a plurality ofV chambers formed therein, one 0f said chambers being arranged to receive a fluid from a space of high pressure in said casing, a conduit connecting the said one of said chambers with a second of said chambers and with a space at super-atmospheric pressure lower than the pressure in the said space of high pressure, a conduit connecting a thirdchamber to a space at sub-atmospheric pressure, an ejector in the conduit connecting the said irst and second chambers operative to cause i'low'of iiuid from the second of said chambers to the said space at super-atmospheric pressure by way of the first said conduit, the said ejector being connected with the said space of high pressure, and a valve controlled by pressure in the second chamber operative to control operation of the said ejector to cause flow of Huidy from the second chamber at such rates as to maintain the pressure therein at substantially atmospheric pressure.

V In testimony whereof I have hereunto subscribed my name this 17 day of March, A. D., 1927, at Zurich, Switzerland.

WILLEM VAN RIJSWIJK. 

